Method of making luggage cases

ABSTRACT

The method of obtaining an accurate interlock between opposing case sections by clamping two edge strips and a tongue strip which are to make up the confronting edges of the case sections in interfitting relation prior to bending, then bending the strips while clamped to effect matched bends and at the same time a permanent locking of the tongue strip in one of the edge strips and matched interfit with the other edge strip. A luggage case is produced by such a method of manufacture.

l Mmmm@mllllllmmlwmmllmmwnml ited "States Patent Jack Slan Toronto, Ontario, Canada 784,510 l Nov. 19, 1968 May 25, 1971 Dominion Luggage Co. Limited Inventor Appl. No. Filed Patented Assignee METHOD OF MAKING LUGGAGE CASES 9 Claims, 13 Drawing Figs. U.S. Cl 29/434, 29/445.v i90/49 Int. Cl ..B23p 19/00, B23p 9/00 Field of Search 29/434,

[56] References Cited UNITED STATES PATENTS 1,555,895 l0/1925 Weber 29/445 3,121,946 2/1964 Young 29/434 Primary Examner-Thomas H. Eager Attorney-Douglas S. Johnson ABSTRACT: The method of obtaining an accurate interlock between opposing case sections by clamping two edge strips and a tongue strip which are to make up the confronting edges of the case sections in interitting relation prior to bending, then bending the strips while clamped to effect matched bends and at the same time a permanent locking of the tongue strip in one of the edge strips and matched intertit with the other edge strip. A luggage case is produced by such a method of manufacture.

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BY 2Mb Attorney PATENTED m25 Isn SHEET 3 UF 4 INVENro/z. JACK sLAN BY mf@ /j/f Attorney PATENTEB m25 197| SHEET k UF 4 INVENTOR. JACK SLAN Attornzy METHOD OF MAKING LUGGAGE CASES BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to improvements in luggage cases and particularly their method of manufacture.

2. Description of the Prior Art Luggage cases nor-mally comprise a first or bottom section and a second or top section hinged together with the sections meeting along the edge when the case is closed, and suitable locks are provided to lock the sections together in the closed position.

Preferably, in an effort to obtain a dustproof case, the sections are arranged to interlock throughout the extent of their opposing or confronting edges andin order to provide an accurate interlock and a proper closure the sections must precisely match one with the other.

With a view to achieving the desired interlock, it has been the practice to form the confronting edges of the case sections of strips of extruded material such as aluminum or a magnesium alloy which are bent around the case, the one strip normally having a groove running around its exposed confronting edge and the other strip having or carrying a projection or tongue member running around its exposed confronting edge adapted to seat in the groove of the opposite strip when the case is closed.

It will readily be understood that one of the problems encountered in such cases is to maintain the mating accuracy of the groove and tongue members or portions particularly around the comers of the case where the strips are bent, such bending tending to stretch, crease, or otherwise distort the material of the strip so that the accuracy of the groove is irnpaired or the tongue member or element is distorted out of alignment with the groove.

Additionally, it has been found thatbending of complicated strip sections particularly those carrying the intended mating tongue member is difficult particularly when a high degree of accuracy is required to provide a proper case closure. This latter problem has led to the use in many instances of a separate tongue member so that the one strip which is intended to carry the tongue member for resting in the groove of the opposing strip is formed as a relatively simple section capable of more readily being bent` around the case and the separate tongue member is then attached thereto.

This latter solution of the bending problem however necessitates the bending of a third member to conform to the peripheral configuration of the case and does not solve the problem of obtaining a precisely mating groove and tongue interlock since the tongue member will invariably have different distortion characteristics.

Moreover, resorting to a separate tongue member requires a further manufacturing operation in attaching the tongue to the relevant strip and attaching it in such a way as to provide strength as well as accuracy SUMMARY OF THE INVENTION It is the object of the present invention to successfully solve the above problems, and to provide a very efficient and simple method of forming the interlocking edges of the case section to provide a precisely accurate edge mating or interlocking between the opposing sections when the case is closed.

ln this same vein it is also the object of the invention to provide a luggage case with precisely interlocking opposing sections to simplify closing and to provide a fully dustproof case.

Another object of the invention is to enable the use of strips of simple readily bendable cross section to make up the con fronting edges of the case section to greatly facilitate manufacture.

In this connection still another object is to enable a separate readily bendable tongue member to be utilized and to cffect the permanent locking of the tongue member with one of the strips and the accurate interfit of the same tongue member with the groove of the other strip by means of the bending operation thereby eliminating a difficult step in manufacturing presently required and at the same time providing a much more accurate tongue and groove interlock than has heretofore been achieved;

The invention will befully understood from the following detailed description taken in conjunction with the accompanyng drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view broken away illustrating the edge and tongue strips and the manner in which they are assembled preparatory to being clamped.

FIG. 2 is a perspective view on a smaller scale illustrating the edge and tongue strips in clamped relation.l

FIGS. 3, 4, 5, and'6 arediagrammatic views illustrating the sequence of bending operations in the bending of the clamped strips into the frame shape of the finished case.

FIG. 7 is an enlarged vertical cross section of the strips after bending illustrating the permanent interlock between the one edge strip and the tongue strip and the releasable interfit between the tongue strip and the other edge strip.

FIG. 8 is a broken away perspective view illustratingthe elongation of the edge strip in which the tongue strip is permanently interlocked as compared to the opposing edge strip.

FIG. 9 is a view of the strips following trimming off of the permanently interlocked edge strip with the strips joined in continuous frame form.

FIG. 10 is a vertical cross-sectional view taken on the line 10-10 ofFIG. 9.

FIG. 11 is an exploded perspective view illustrating the assembly of the shell, lock and handle members to the frame members formed by the strips.

FIG. 12 is a part perspective part vertical sectional view showing the manner in which the shells are attachedto the edge strips and in which-the wrap around strips masks the attached means.

FIG. 13 is a perspective view of a case manufactured in accordance with and embodying the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference tothe drawings, FIG. 13 illustrates a luggage case constructed in accordance with and embodying the invention. In general the case comprises a pair of opposing sections 1, la, hinged together as at 2 and presenting confronting edges generally designated at 3` and 3a adapted to interfit when the case is closed. The method of manufacture and the construction of the confronting edges 3 and 3a, is one important aspect of the invention, which is particularly illustrated in FIGS. 1 to 8 inclusive.

With reference to FIG. 1 the confronting edges 3 and`3a of the sections l and 1a are formed from two longitudinal edge strips 4 and 4a preferably formed as extrusions of a light metaldercut edges 1l and l2. The edge strip 4a is very similar to the edge strip 4 having an attaching leg 6a, a facing leg 7a and an upper channel 10a, having undercut edges lla and 12a. The channel 13 presented by the facing leg 7a, however is formed with a wide divergent mouth defined by walls 14 and 15 which diverge towards the mouth of the channel.

In association with the edge strips 4 and 4a, the tongue strip 5 has along one longitudinal edge a locking enlargement or bead 16 having somewhat the shape of an arrowhead and defining shoulders 17. The bead 16 -is of a cross-sectional shape to correspond with the cross-sectional shape of the channel 8.

The opposite longitudinal edge of the tongue strip 5, also preferably has an edge bead 18 of corresponding shape, the beads in addition to providing the functions hereinafter described also serving to increase the stiffness of the tongue strip.

In the manufacture of the case it will be understood that the edge strips 4 and 4a will be cut to a length such that on bending they will provide the requisite peripheral configuration and dimensions of the case. After cutting the edge strips 4 and 4a to length, a tongue strip 5 also cut to the appropriate length is assembled with the edge strip 4 by sliding its bead 16 into the channel 8 with the mouth of the channel engaging behind the shoulders 17 to provide a snug interlock between the strips 4 and 5. The other edge strip 4a is then assembled with the interlocking strips 4 and 5 so that the edge bead 18 of the strip 5 is received in the divergent-mouthed channel 13. The strips 4, 4a, and 5 thus assembled are clamped together by means of suitable clamps 19. If it is desired that one edge of the case might be in the form of a shallow arc, the clamp strips 4 4a and 5 are first bowed as illustrated in FIG. 3. Subsequently these strips while still clamped are bent as at 20, FIG. 4, to form one comer of the case, as at 2l, FIG. 5, to form a second corner of the case and as at 22 and 23, FIG. 6, to form the remaining comers of the case.

In the bending operation it will be understood that the bending will proceed successively from bend to 23 while the strips are clamped with the bending of each successive bend being away from the previous bend as illustrated so that any tendency of the tongue strip 5 to elongate during the bending operation will be accommodated by the flow of the tongue strip in the channels 8 and 13 relative to the edge strips 4 and 4a, outwardly of the bend. With this sequence there will be no crowding of the tongue strip between bends, that is no longitudinal compression of the tongue strip between bends. The above described bending sequence eliminates this longitudinal compression but it will be appreciated that so long as bending proceeds away from the previous bending, other bending sequences may be used.

By bending the strips 4, 4a and 5 while in clamped relationship, the simultaneous bending of the strips provides precisely matched bends in the strips for the ultimate guarantee of accurate matching of the confronting edges of the case and the proper interfit of the case sections.

lthas been discovered that by making a snug fit or interlock between the one strip 4 and the tongue strip 5, the bending operation itself through the distortion of the walls of the channel 8 relative to the tongue 5 particularly around the corners, causes an effective clamping of the tongue by the walls of the channel 8 and particularly by the lips 24 which become anchored in behind the bead shoulders I7 as particularly seen in FIG. 7.

In contrast the relatively free fit of the bead 18 in the channel 13 and the divergence of the channel I3 and the taper of the bead 18 enables any distortions in the metal of the strip 4a under bending to be accommodated without an actual interlock being elected so that a snug accurate interfit between the bead 18 and the channel I3 is achieved on bending but the strip 4a is readily separable from the tongue 5.

Following the bending operation, the strips are then unclamped and the removal of the edge strip 4a from the now permanently interlocked strips 4 and 5 releases the tongue strip 5 from any restraint and it has been found that the tongue strip elongates slightly on release.

After the strip 4a has been unclamped and removed, to free the interlocked strips 4 and 5 to assume an unrestrained position, the strip 4a is again assembled with the strips 4 and-5 and clamped in position.

Under the bending operation strip 4 elongates more than the edge strip 4a. This elongation appears to be caused by the fact that the metal of the strip 4 in the area of the channel 8 once it reaches the limit of compression of the tongue bead I6 is restrained from further deformation in a direction perpendicular to the tongue and as a result the metal in the strip flows along the tongue. On the other hand, because during the bend ing operation the divergent walls of the channel 13 can act on the tapered bead 18 to expel the tongue from the channel there is not the same restriction to the deformation of the metal of the strip 4a in a direction perpendicular to the tongue and its elongation is therefore substantially less.

FIG. 8 illustrates the relative difference in the lengths of the strips 4 and 4a so that a further step following the reclamping of the strip is to trim off the strip 4 so that it matches the strip 4a and the strips can be closed as illustrated in FIG. 9. The ends of the strips 4 are then secured together by means of a joiner clip 25 secured by the rivets 26. The ends of the strip 4a are secured together by being riveted to one element 27 of one of the hinges generally designated at 2. Next the locking tongues 28 illustrated in FIG. 13 may be riveted in position and holes 29 drilled in the tongue strip 5 preparatory to securing the other element or ann 30 of the hinge 2 to the interlocked strips 4 and 5. Also the necessary openings for the fasteners for the locks 31 illustrated in FIG. l1 may be formed in the tongue strip 5 while the strips are still clamped in assembled relation.

Next the strips are separated. The strips 4 and 5 now in effect constitute in the form of a generally rectilinear frame,` the confronting edge 3 of one of the sections, and the strip 4a constitutes, again in the form of a generally rectilinear frame, the confronting edge 3a of the other section.

In order to give support for the hinges 2 a backing strip 32 is applied to the inside of the tongue strip 5 as illustrated in FIG. I l and the hinge elements 30 are fastened to the tongue strip 5 as reinforced by the backing strip 32 by means of suitable fasteners 33 passing through the tongue holes 29 and through the backing strip 32.

The walls of the sections 1 and 1a of the case are preferably formed of moulded plastic shells 34. These shells preferably having their insides surfaces coated with glue are assembled with each of the confronting edge frames 3 and 3a by stitching as illustrated in FIG. 12. In this FIG. it will be seen that the shell 34 seats under the attaching leg 6 of the strip 4 and vabuts behind the channel 8. Wire stapling or stitching indicated at 35 anchors the shell to the attaching legs 6. Similarly, the other shell is attached to the leg 6a of the strip 4a. The shells are then lined with the lining adhering to the glue-carrying inner surfaces of the shell and the requisite pockets 36, retaining straps 37, dividing curtain 38 with swivel locks 39, or other interior decor are added.

To cover the staples 35 and other fasteners such as 26 and 33, a wraparound strip 40 is mounted in each of the channels 10, 10a formed in the outer face of the attaching legs 6 and 6a respectively with the edges of the strip 40 being interlocked beneath the undercut edges 1l and l2 and lla and 12a as exemplifled in FIG. l2.

The locks 3l may be conveniently mounted on the tongue strip portion 5 opposite to the hinges 2 and an appropriate lock cover plate 4l forming a handle mount applied and the handle 42 may then be attached in position.

It will be understood that the precise sequence of steps is not material to the invention and will depend upon the interior decor of the case and the manner of mounting the various hardware components within the case.

It will be understood that the manufacture of the case in accordance with the method disclosed will provide precisely matched bends at the corners 20, 2l, 22, and 23 which can only be achieved with high precision when the bending is carried out with the strips 4, 4a and 5 in interlocked relation. It will also be understood that the actual operation of bending provides the interlock between the strip 4 and the strip 5 without requiring any additional operation for attaching a tongue to one of the edge strips.

lt is important that the tongue strip be a member separate from the edge strips 4 and 4a since it is extremely difficult to bend an extrusion whose section is complicated particularly with a wide projection corresponding to the width lof the tongue strip 5. Because the tongue strip 5 is free to flow longitudinally of the edge strips 4 and 4a during the bending operation under the progressive successive bends, the tongue strip does not provide an impediment to the bending of the relatively simple edge sections 4, 4a, which thus can be bent without appreciable distortion.

It will be understood that the method of manufacture leads to a case which has a more accurate closing action than previous cases which heretofore have not had precisely matched comers, or precisely interfitting members capable of providing an accurate fit completely matched around the case at all times.

It will be understood that the actual configuration of the case may be other than the simple rectilinear form illustrated and various modifications and alterations may be made in the section shapes of the strips and other details without departing from the spirit of the invention or the scope of the appended claims.

[claim:

1. ln the manufacture of a luggage case having opposing sections whose confronting edges are adapted to interf'it when the case is closed, the steps of:

forming the confronting edges of the case sections of a pair of longitudinal bendable edge strips and a longitudinal bendable tongue strip; effecting a snug interfit between one longitudinal edge of said tongue strip and a first one of said edge strips and a loose interfit between the other longitudinal edge of saidV tongue strip and the second one of said edge strips;

clamping said edge strips in such assembled relation with said tongue strip;

and bending said strips while so clamped into thedesired peripheral configuration of the confronting case edges of the case to effect permanently interlocking of said tongue strip and said first edge strip and an accurate mating interfit of said tongue strip with said second edge strip.

2. In the manufacture of luggage cases as claimed in claim l the further steps of:

unclamping said strips after bending and removing said second edge strip from said permanently interlocked tongue and first edge strips to relieve stresses;

reassembling said second edge strip in interfitting relation with said tongue and first edge strip;

then trimming off any difference in length of edge strips produced on bending and joining the ends of each of said edge strips;

then reseparating said second edge strip from said permanently interlocked tongue and first strip;

and attaching concave shells to each of said strips to form the walls of the case sections.

3. ln the manufacture of a luggage case having opposing sections whose confronting edges are adapted to interfit when the case is closed, the steps of:

inserting one edge of a longitudinal bendable strip of plastic material into a groove shaped to snugly receive said edge formed in a first metallic strip adapted to form the confronting edge of one of said case sections;

introducing thev other edge of said plastic strip into a groove shaped to relatively loosely receive said other edge formed in a second metallic strip adapted to form the confronting edge of the other of said case sections; clamping said strips together;

then bending said strips to the desired peripheral case configuration to pennanently interlock said plastic strip with said first metallic strip while effecting a releasably interfit registration of said plastic strip with said second metallic strip.

4. ln the manufacture of a luggage case having opposing sections adapted to interfit throughout their confronting edges when the case is closed, the steps of:

inserting one edge of a longitudinal stiff tongue-forming strip of bendable material into a mating groove having a mouth closely fitting o n the strip formed in a longitudinal one of the case sections;

introducing the other edge of said tongue-forming strip into a mating groove having a relatively wider mouth than said closely fitting mouth formed in a longitudinal bendable strip adapted to bound the confronting edge of the other case section;

clamping said strips in interfitted relation;

bending said strips while clamped into the desired 'peripheral case configuration with the bending proceeding such that each bend is bent away from the previous bend to accommodate any longitudinal movement of said tongue-forming strip relative to said other strips, the bending effecting a permanent interlock of said one edge of said tongue-forming strip in said mating groove having said closely fitting mouth and an accurate releasable interfit registration of the other edge of said tongue-forming strip with said mating groove having said relatively wider mouth.

5. ln the manufacture of a luggage case as claimed in claim 4 the further steps of:

unclamping said strips and separating said strip having said wider mouth groove from said permanently interlocked strips to relieve stresses;

reclamping said strips together in interfitted relation;

and trimming off any excess length of said permanently interlocked strips over the length of strip having said wider mouth groove.

6. ln the manufacture of a luggagecase as claimed in claim 5 the further steps of: i

connecting the adjoining ends of said strip with `which said tongue-forming strip is permanently interlocked with a joiner clip;

and connecting the ends of said strip having said wider groove with one element of a hinge while said strips are still clamped while leaving said hinge unattached to said permanently interlocked strips;

unclamping said strips and separating said permanently locked strips from said strip having said wider mouth groove;

and attaching concave shells to each of said strips adapted to bound the confronting edges of said case sections.

7. In the manufacture of a luggage case as claimed in claim 6 the further steps of reassembling said strips in interfitting relation and securing said hinge to said permanently interlocked strips.

8. The method of providing accurately matching interfitting confronting edges on opposing sections of a luggage case comprising;

forming the confronting edges of the case sections of a pair of longitudinal edge strips and a longitudinal tongue strip, each of said edge strips having a first leg for attachment to a casing shell and a second right angular leg adapted to form a confronting edge face, the second leg of a first one of said edge strips presenting a longitudinal channel therein formed with a restricted mouth, the second leg of the second one of said edge strips presenting a longitudinal channel therein formed with a divergent mouth and said tongue strip having a shouldered enlargement along one longitudinal edge adapted to snugly interlock in said restricted mouth channel, the other edge of said tongue strip being adapted to be received in said divergent mouth channel;

inserting said shouldered enlargement of said tongue strip into said restricted mouth channel and said other tongue edge into said divergent mouth channel to bring said strips into assembled relation;

clamping said strips in assembled relation;

and bending said strips in unison while clamped into the desired peripheral configuration of the case sections with the bending proceeding from one bend to the next while bending away from the previous bend to accommodate any longitudinal movement of said tongue strip relative to said edge strips, the bending effecting a permanent interlock of said shouldered enlargement of said one tongue from said permanently interlocked first edge and tongue strips to relieve any stresses;

said strips are then reassembled and clamped together in intertted relation and any excess length of said first edge strip over said second edge strip is trimmed. 

1. In the manufacture of a luggage case having opposing sections whose confronting edges are adapted to interfit when the case is closed, the steps of: forming the confronting edges of the case sections of a pair of longitudinal bendable edge strips and a longitudinal bendable tongue strip; effecting a snug interfit between one longitudinal edge of said tongue strip and a first one of said edge strips and a loose interfit between the other longitudinal edge of said tongue strip and the second one of said edge strips; clamping said edge strips in such assembled relation with said tongue strip; and bending said strips while so clamped into the desired peripheral configuration of the confronting case edges of the case to effect permanently interlocking of said tongue strip and said first edge strip and an accurate mating interfit of said tongue strip with said second edge strip.
 2. In the manufacture of luggage cases as claimed in claim 1 the further steps of: unclamping said strips after bending and removing said second edge strip from said permanently interlocked tongue and first edge strips to relieve stresses; reassembling said second edge strip in interfitting relation with said tongue and first edge strip; then trimming off any difference in length of edge strips produced on bending and joining the ends of each of said edge strips; then reseparating said second edge strip from said permanently interlocked tongue and first strip; and attaching concave shells to each of said strips to form the walls of the case sections.
 3. In the manufacture of a luggage case having opposing sections whose confronting edges are adapted to intErfit when the case is closed, the steps of: inserting one edge of a longitudinal bendable strip of plastic material into a groove shaped to snugly receive said edge formed in a first metallic strip adapted to form the confronting edge of one of said case sections; introducing the other edge of said plastic strip into a groove shaped to relatively loosely receive said other edge formed in a second metallic strip adapted to form the confronting edge of the other of said case sections; clamping said strips together; then bending said strips to the desired peripheral case configuration to permanently interlock said plastic strip with said first metallic strip while effecting a releasably interfit registration of said plastic strip with said second metallic strip.
 4. In the manufacture of a luggage case having opposing sections adapted to interfit throughout their confronting edges when the case is closed, the steps of: inserting one edge of a longitudinal stiff tongue-forming strip of bendable material into a mating groove having a mouth closely fitting on the strip formed in a longitudinal bendable strip adapted to form the confronting edge of one of the case sections; introducing the other edge of said tongue-forming strip into a mating groove having a relatively wider mouth than said closely fitting mouth formed in a longitudinal bendable strip adapted to bound the confronting edge of the other case section; clamping said strips in interfitted relation; bending said strips while clamped into the desired peripheral case configuration with the bending proceeding such that each bend is bent away from the previous bend to accommodate any longitudinal movement of said tongue-forming strip relative to said other strips, the bending effecting a permanent interlock of said one edge of said tongue-forming strip in said mating groove having said closely fitting mouth and an accurate releasable interfit registration of the other edge of said tongue-forming strip with said mating groove having said relatively wider mouth.
 5. In the manufacture of a luggage case as claimed in claim 4 the further steps of: unclamping said strips and separating said strip having said wider mouth groove from said permanently interlocked strips to relieve stresses; reclamping said strips together in interfitted relation; and trimming off any excess length of said permanently interlocked strips over the length of strip having said wider mouth groove.
 6. In the manufacture of a luggage case as claimed in claim 5 the further steps of: connecting the adjoining ends of said strip with which said tongue-forming strip is permanently interlocked with a joiner clip; and connecting the ends of said strip having said wider groove with one element of a hinge while said strips are still clamped while leaving said hinge unattached to said permanently interlocked strips; unclamping said strips and separating said permanently locked strips from said strip having said wider mouth groove; and attaching concave shells to each of said strips adapted to bound the confronting edges of said case sections.
 7. In the manufacture of a luggage case as claimed in claim 6 the further steps of reassembling said strips in interfitting relation and securing said hinge to said permanently interlocked strips.
 8. The method of providing accurately matching interfitting confronting edges on opposing sections of a luggage case comprising; forming the confronting edges of the case sections of a pair of longitudinal edge strips and a longitudinal tongue strip, each of said edge strips having a first leg for attachment to a casing shell and a second right angular leg adapted to form a confronting edge face, the second leg of a first one of said edge strips presenting a longitudinal channel therein formed with a restricted mouth, the second leg of the second one of said edge strips presenting a longitudinal channel therein formed with a divergent mouth and said Tongue strip having a shouldered enlargement along one longitudinal edge adapted to snugly interlock in said restricted mouth channel, the other edge of said tongue strip being adapted to be received in said divergent mouth channel; inserting said shouldered enlargement of said tongue strip into said restricted mouth channel and said other tongue edge into said divergent mouth channel to bring said strips into assembled relation; clamping said strips in assembled relation; and bending said strips in unison while clamped into the desired peripheral configuration of the case sections with the bending proceeding from one bend to the next while bending away from the previous bend to accommodate any longitudinal movement of said tongue strip relative to said edge strips, the bending effecting a permanent interlock of said shouldered enlargement of said one tongue edge in said restricted mouth channel to permanently lock said tongue to said first edge strip and effecting an accurate releasable interfit registration of said other tongue edge with said divergent mouth channel of said second edge strip.
 9. The method as claimed in claim 8 on which said strips are unclamped after bending and said second edge strip separated from said permanently interlocked first edge and tongue strips to relieve any stresses; said strips are then reassembled and clamped together in interfitted relation and any excess length of said first edge strip over said second edge strip is trimmed. 